Videos in my library won't play on Apple Music

Make a backup if you don't already have one. Delete an affected item from your library without deleting from your purchase history. You may get two or three confirmation prompts, delete from library, send to trash, delete from purchase history. Right-click the cloud version of the item that should remain and click Download. If the item disappears when you delete it close Music and reopen, it should come back as a cloud link. Obviously all this only applies to purchased items.

tt2

You cannot reinstall the Music app. Your would need to reinstall the entire OS to repair it, assuming it needs repairing. If these are purchased items you can try removing your local copy and then redownload. I'm assuming that purchases were made with the ID you're currently using and that the computer is authorized to your Apple ID.

tt2

Hi Sonjastwin,

It sounds like the Music App shows blank videos on your Mac. We're glad you've joined us in Apple Support Communities. Let's see if this helps.

It looks like you've had the chance to review Find answers and ask questions in Apple Support Communities. That's a great start, but we have some additional advice for you.

This sounds possibly network related. When this happens if you go to open a webpage in an app like Safari, does it open? How do you normally connect to the internet? Check out, Connect to the internet with your Mac for the methods in which you can connect a Mac to the internet.

If the issue remains, let's follow the steps in If an app on your Mac stops responding, closes unexpectedly, or won’t open. The troubleshooting in it will commonly fix issues of apps not working properly on your Mac. Since you mentioned updating already, you can skip steps three and four as they don't apply to your specific situation. 

If the issue remains, let us know if the issue resolves after a restart as outlined in step two. 

Best!